This section provides background information related to the present disclosure, which is not necessarily prior art.
With reference to FIGS. 1 and 2, an existing blower assembly, such as a blower assembly for a heating, ventilation, and air conditioning (HVAC) unit for a vehicle, is generally illustrated at reference numeral 10. The blower assembly 10 generally includes a centrifugal fan 12 and a scroll casing 14. The centrifugal fan 12 defines an air inlet 20 at a center thereof for receipt of airflow A. The centrifugal fan 12 defines a plurality of air outlets 22 about an outer periphery thereof. A plurality of blades 24 are provided at the air outlets 22 in order to direct airflow A exiting the air outlets 22. The centrifugal fan 12 rotates about an axis at an axial center of the air inlet 20.
The scroll casing 14 includes a side scroll casing 30, generally extending around a portion of the centrifugal fan 12 from a scroll starting position 32 to a scroll ending position 34. An air outlet 36 of the blower assembly 10 extends from the scroll ending position 34 to an outlet aperture 38 at which airflow A exits the blower assembly 10. The air outlet 36 defines the outlet aperture 38.
A window 40 is defined between the side scroll casing 30 and the centrifugal fan 12 proximate to the scroll starting position 32. At the scroll starting position 32 is a partition 42, which at least partially defines the window 40. The partition 42 generally separates or partitions the side scroll casing 30 from the air outlet 36, and can be any suitable partition, such as a vertical partition or nose. The partition generally extends vertically, such as along line B (FIG. 2) relative to a lower surface 44 of the scroll casing 14.
The lower surface 44 of the scroll casing 14 is generally recessed below a ring-shaped planar face 46. The ring-shaped planar face 46 at least partially defines a central aperture 48 (see FIG. 3, which includes the central aperture 48 and features according to the present teachings as described herein) at which the centrifugal fan 12 is seated. The ring-shaped planar face 46 thus generally surrounds the centrifugal fan 12. The ring-shaped planar face 46 and the lower surface 44 of the scroll casing 14 extend in generally parallel and spaced apart planes, with the ring-shaped planar face 46 extending in a plane above the lower surface 44, as particularly illustrated in the orientation of FIG. 2, for example.
Extending between the ring-shaped planar face 46 and the lower surface 44 is a sloped face 50. The sloped face 50 may extend directly from the ring-shaped planar face 46, or from an intermediate surface (not shown) therebetween, which may be angled or sloped toward the lower surface 44. The sloped face 50 slopes radially outward from the ring-shaped planar face 46 (or the intermediate surface) to the lower surface 44 at generally a constant slope in an area between the scroll starting position 32 and the scroll ending position 34.
The sloped face 50 includes a sloped transition portion 52 extending beyond the scroll ending position 34 in the direction of the outlet aperture 38, which is a downstream direction relative to airflow A flowing through the scroll casing 14 out from within the centrifugal fan 12. The sloped transition portion 52 angles radially inward towards the centrifugal fan 12 as the sloped transition portion 52 extends away from the scroll ending position 34 in the downstream direction. The sloped transition portion 52 extends to vertical sidewall 60, which may begin proximate to the partition 42 (as illustrated in FIG. 1) or downstream of the partition 42 closer to the outlet aperture 38.
A planar guide wall or surface 62 extends from the ring-shaped planar face 46 towards the partition 42. An outer edge of the planar guide surface 62 proximate to the air outlet 36 extends from the ring-shaped planar face 46 in generally a tangential direction to the partition 42. Thus at the partition 42, the planar guide surface 62 extends generally in a plane that is perpendicular to line B extending along a height of the partition 42, as illustrated in FIG. 2 for example.
As airflow A exits the air outlets 22, such as proximate to the partition 42, airflow A may contact the planar guide surface 62 and or the partition 42, thereby causing an airflow disruption D. The disruption D may generate a sound, which is generally undesirable. A blower assembly that eliminates or minimizes airflow disruptions, such as disruption D, and sounds associated therewith, would therefore be desirable.